Ratchet mechanism



Feb. 26, 1963 L. E.- KILNESS RATCHET MECHANISM 2 Sheets-Sheet 1 FiledJune 30, 1961 /0 INVENTOR. LUTHER E. K/L/VE-S'S 1 /8 BY ATTORNEYS Feb.26, 1963 1.. E. KILNESS 3,

RATCHET MECHANISM Filed June 30, 1961 2 Sheets-Sheet 2 INVENTOR. LUTHER.E. K/LA/E53 BY W 21 ya A TTORNEYS This invention relates to ratchetmechanisms and more particularly to reversible ratchet wrenches.

The primary object of the invention is the improvement of the controlsfor the pawl shown in my United States Patent No. 2,5 54,990.

Another object is to provide eiiicient coupling between pawls whichutilize all teeth for driving in both directions and a manual reversecontrol.

Still another object is to provide simplified coupling between one-piecereversible pawls carried by the workturning member and pawl shiftingelements which may be operatedby a directional manual reverse on thehandle.

A further object is to provide reliable and inexpensive pawl controlsadapted for use with pawl systems carried by the work-turning member.

Other objects and advantages of the invention will be apparent from thedescription and accompanying drawings.

In the drawings, FIGURE 1 is a perspective view of a ratchet wrenchillustrating the invention and shown in more detail in FTGURES 2 through5.

FTGURE 2 is a sectional view of the head of the wrench taken on the line2-2 of FIGURE 5.

FIGURE 3 is a sectional view taken on the line 3-3 of FIGURE 5.

FIGURE 4 is a detail perspective view of a control spring and shift pin.

FIGURE 5 is a vertical section taken substantially through the center ofthe wrench head.

FIGURES 6 and 7 are transverse and vertical sections respectively of amodification of the invention. FTGURE 6 is taken along the line 6-6 ofFIGURE 7.

The embodiment of the invention shown in FIGURES 1 through 5 has adriving member 1i? having a head 11 at one end. The other end of thedriving member has a handle grip 12. The head 11 has a cylindricalopening 13 formed with internal ratchet teeth 14. A work-turning member15 is journalled in the cylindrical opening by small flats on the teeth14-. A flan e 16 on the workturning member bears against a shoulder inthe cylindrical opening 13 for positioning the work-turning member inthe opening. The work-turning member 15' is retained in assembly by asplit retaining ring 17 which is entered in a groove in the head 11. Thework-turning member has a square 18 at one end for holding detachablesockets. A cap or cover plate it? closes the top of the head 11 and isretained by a split ring 2%? which fits inside grooves in the head 11and the cover plate 19. The ends of the split ring 21') are formed withindentations extending into recesses 21 and 22, in the cover plate 19 topermit assembly and disassembly of the cover plate.

A pawl 23 is carried in a concave recess or chamber 24 on the side ofthe work-turning member 15. The pawl 23 has an arcuate side with aseries of teeth 25 adapted to concurrent and reversible engagement withthe teeth 14- in the head 11. The pawl is of smaller size than therecess 24 to permit circumferential displacement of the pawl andwithdrawal of the pawl teeth from the teeth 14. The pawl 23 has twooppositely positioned surfaces for transmitting thrust in two directionsthrough or relative to the pawl body to opposing ends of the recess 24.The ends of the recess converge toward each other in a direction awayfrom the teeth 14. The pawl 23 is resiliently held against the teeth 14by a spring 26 contained in a bore in the pawl Patented Feb. 26, li53and which pushes outwardly against a ball 27. The ball engages an innersurface of the concave recess 24.

A control plate 28 has an extension 29 on one side which engages pins3t) and 31 on the pawl 25 for directing the pawl toward either end ofthe concave recess. The extension 29 is narrower than the spacingbetween the pins 3% and 31 to permit freedom of movement for the end ofthe pawl not engaged by the extension. The control plate 28 ispositioned in a concentric recess on top of the work-turning member. Theinner wall of the concentric recess forms a hub 32 for rotata-blymounting the control plate. The top of the hub 32 is peened over againsta beveled surface on the control plate 28 to hold the control plate inassembly.

The control plate 23 and two control springs 33 and 34 provideresiliently-acting means for biasing the pawl toward a selected end ofthe recess 24. The resilientlyacting means is employed as a connectionor coupling between the pawl and manually adjustable controls, ashereinafter described. The control plate 28 is urged in opposingdirect-ions by the control springs 33 and 34. An arm 35 of the controlspring 33 engages a bent-up projection 35 of the control plate to urgethe control plate in a counterclockwise direction. An arm 37 of thecontrol spring 34 is entered in a small hole 33 in the control plate 28to urge the control plate in a clockwise direction. For the controlspring positions shown in FEGURE 2, the control spring 33 exerts agreater turning force on the control plate 23 than the lesser controlspring 34 does and urges the control plate in a counterclockwisedirection. With the arm 35 of the control spring 33 shifted to theposition shown by the dotted lines in FIGURE 2, the lesser controlspring 34 takes over and urges the control plate 28 in a clockwisedirection.

The control spring 33 has a U-shaped section 39 which is contained in ahole 49 near the periphery of the workturning member 15. The U-shapedsection 3% may be made with one or more loops and provides torsionalspring action. An end 4-1 of the control spring 33 is secured in a smallhole 42 in the work-turning member 15 to serve as a reference for thespring action.

The control spring 3 is contained in a hole 43 in the work-turningmember 15. The hole $3 is of sufiicient size to allow unrestrictedmovement of the arm 37 which engages the control plate The other end 44of the control spring 334 is secured in a small hole 45 in theworkturning member 15 for maintaining the correct operative position ofthe control spring 34.

A shift pin 46 is mounted for vertical adjustment in the work-turningmember 15 in a hole 47 which parallels and is located at the axis ofrotation of the work-turning member. The shift pin d6 may be selectivelymoved to either of two operable positions at different elevations withrespect to the work-turning member. The shift pin 46 has a conicallyexpanded head which is received by a countersunk portion of the axialhole 4 7 when the shift pin is is in its extreme downward position. Thediverging surface of the head of the shift pin 46 displaces the arm 35of the control spring 33 when the shift pin is moved down. The arm 35 ispreferably displaced far enough to break contact with the bent-upprojection of the control plate 28 and permit the other control spring3% to take over without restricting its range of action. The upwardreturn movement of the shift pin is provided, at least in part, by thevertical component of force exerted on the head of the shift pin 46 bythe arm 35 of the control spring 33. A spring 48 may be placed in theaxial hole to ensure the upward movement of the shift pin 46.

Manual control of the direction of driving is given by a reverse controlmember which determines the vertical adjustment of the shift pin 46. Inthis embodiment, the reverse control member consists of a shift bar 49which has two positions relative to the head Ill for indexing thedirection of driving. The shift bar 49 has an inclined surface 56adapted to engage the slightly rounded top of the shift pin 46 and todepress the shift pin when the shift bar is moved forward. The coverplate 19 has an elongated recess 51 to receive the shift bar 49 andpermit limited forward movement. The wrench head ll is made with achannel 52 adjacent the cylindrical opening 13 to accommodate the shankof the shift bar 49. The back portion of the shift bar is provided withsuitable gripping means to give easy manipulation for both forward andbackward movement.

In operation, with the shift bar i) in retracted position as shown inFIGURES 3 and 5, the shift pin 46 would be in the position shown inFIGURE 5. The control spring 33 would then predominate over the controlspring 34 to urge the control plate 28 counterclockwise. The pawl 23would be driven by the control plate to the counterclockwise end of theconcave recess 24 as shown in FIGURE 2. Turning the handlecounterclockwise would wedge the pawl 23 between the teeth 14 in thehead 11 and the walls of the concave recess 24 for driving the work in acounterclockwise direction. Turning the handle clockwise would releasethe pawl 23 from locking engagement and cause the pawl to engagesuccessive series of teeth 14 in the head 11 until the handle was againturned counterclockwise for the driving stroke.

For driving in a clockwise direction, the shift bar 49 is moved forwardto depress the shift pin 46. In its extreme forward position, thehorizontal bottom surface of the shift bar extends past the center ofthe shift pin. The vertical pressure from the shift pin 46 on thehorizontal bottom surface of the shift bar 49 maintains the shift bar inthe forward position. With the shift pin in its lowest position, thecontrol spring 33 would be disengaged from the control plate 28. Thecontrol spring 34 would then take over and urge the control plate in aclockwise direction. Thepawl 23 would be directed by the control plate28 to the clock-wise end of the concave recess 24 for driving the workin a clockwise direction and for releasable ratcheting action in acounterclockwise direction.

FIGURES 6 and 7 show the invention in application to small rim or ledge67 for positioning the control springs I 63 and 64-. The rim 67 may beundercut inside for holding a conventional pawl 53. The wrench head 54should be larger than the wrench head of the previously describedembodiment because the conventional pawl 53 engages the wrench head 54with only a few teeth and increases the stress concentration on thewrench head. In addition, the internal teeth 55 in the wrench head 54should not be broached through in order to leave a continuous bearingsurface for the upper portion of the work-turning member 56.

The pawl 53 shown in FIGURES 6 and 7 is a one-piece pawl contained in aslot or chamber 60 formed on the side of the work-turning member 56. Thepawl 53 has teeth 57 on opposite ends 58 and 59. The pawl teeth on theend 58 engage the teeth 55 for driving in a counterclockwise direction,and the pawl teeth on the end 59 engage the teeth 55 for driving in aclockwise direction. The ends of the pawl transmit thrust from the teeth55 in two different directions or paths through the pawl to a shaft 61.The shaft 61 passes through the slot and has bearing support on bothsides of the slot. The shaft 61 is pressed into a central hole in thepawl 53 or otherwise secured to the pawl so that the pawl and shaftrotate as a unit. The limited rotational motion of the pawl 53 withinthe slot 66 is sufiicient to bring either toothed end of the pawl intoengagement with the teeth 55 in the head 54 while the other toothed endis free from engagement.

The top of the shaft 61 is formed with a crank 62 for turning the shaftand associated pawl in either direction. Control springs 63 and 64-engage the crank 62 for urging the pawl 53 in either a clockwise orcounterclockwise direction. The control springs 63 and 64 arehorizontally placed on top of the work-turning member 56 and have bookedends entered in small holes 65 and 66 in the workturning member. Thework-turning member 56 has a the control springs 63 and 64 close to thetop of the workt-urning member 56.

When the shift pin 46 is in its highest vertical position, the controlspring 63, which provides the greatest force, will override the actionof the control spring 64 and urge the pawl 53 to the position shown inFIGURE 6. The pawl 53 will be releasably held against the teeth 55 inthe head 54 for driving the work in a counterclockwise direction.Depressing the shift pin 46 with shift bar 4-9 will force the controlspring 63 from engagement with the crank 62 and permit the lessercontrol spring 64 to take over and swing the crank in a clockwisedirection to bring the other end 59 of the pawl 53 into engagement withthe teeth in the head 54, for driving in a clockwise direction.

While the invention has been shown and described in preferred forms,modifications may be made in various features of the invention by thoseskilled in the art. The dual control spring arrangement shown here maybe applied to a reversible pawl of the type shownin FIGURE 2 but carriedby the wrench head instead of the work-turning member. Changes may bemade in the spring connections for the combination of one-piecereversible pawls and vertically adjustable control elements whileretaining the advantages of resilient coupling for this particularapplication. Other changes may be made without departing from theinvention as defined in the following claims.

What is claimed is:

1. In a ratchet mechanism, the combination of a driving member having ahead, a work-turning member mounted for rotation in said head,reversible pawl means carried by said work-turning member for drivingengagement with the head, and control means for directing the pawl meansin reversible engagement with the head, said control means including twoyieldable members mounted on said work-turning member and acting on thepawl means with unequal force, one of said yieldable members urging thepawl means in a direction to drive one way and the other yieldablemember urging the pawl means in a direction to drive the opposite way,said control means including displacement means for moving the greaterof the two yieldable members in such a direction as to relieve itspressure on the pawl means and permit the lesser of the two yieldablemembers to determine the direction of ratchet driving, the greater ofthe yieldable members predominating to determine the direction ofratchet driving in an undisplaced state.

2. A ratchet mechanism according to claim I, wherein said displacementmeans comprises an adjustable member carried by said work-turning memberand having two operable positions in a direction paralleling the axis ofrotation of said work-turning member, said adjustable member being soformed as to displace the greater of the yieldable members in oneoperable position.

3. Ina ratchet mechanism, the combination of a memher having a head, awork-turning member rotatably mounted in said head, one of said membershaving a circular toothed surface, a pawl carried by the other of saidmembers in position to engage the circular toothed surface, said pawlhaving an arcuate side provided with teeth, said pawl being adapted forreversible engagement with the circular toothed surface with all of thepawl teeth being used for driving in both directions, and control meansfor bringing the pawl into reversible engagement with said circulartoothed surface, said control means including two yieldable membersacting on the pawl in opposing directions and of unequal magnitude, oneof said yieldable members urging the pawl into position to drive in onedirection and the other of said yieldable members urging the pawl intoposition to drive in the opposite direction, the greater of saidyieldable members predominating to-direct the pawl for engagement withsaid circular toothed surface for one direction of driving, said controlmeans further including means for relieving the force acting on .thepawl from the greater of the yieldable members, whereby the lesser ofthe yieldable members may direct the pawl for engagement with saidcircular toothed surface for driving in the opposite direction.

4. In a ratchet mechanism, the combination of a member having a head andanother member rotatably mounted in said head, one of said membershaving a circular toothed surface and the other of said members having arecess open to said circular toothed surface, a pawl carried in saidrecess, said pawl being of smaller size than the recess to permitcircumferential displacement of the pawl and withdrawal from thecircular toothed surface, said recess having two ends adapted to engagethe pawl for receiving the thrust of the pawl, the ends of said recessconverging toward each other in a direction away from the circulartoothed surface, one end of the recess receiving the thrust of the pawlfor one direction of driving and the other end of the recess receivingthe thrust of the pawl for the other direction of driving, said pawlhaving an arcuate side having teeth adapted to concurrent drivingengagement with said circular toothed surface, all of said pawl teethbeing used for driving in both directions, and control means forbringing the pawl into reversible engagement with the circular toothedsurface, said control means including resilientlyacting means forselectively directing the pawl toward either one of said ends of therecess, said resiliently-acting means comprising two spring means actingon the pawl in opposite directions, one of said spring means urging thepawl toward one end of said recess while the other of said spring meansurges the pawl toward the ther end of said recess, said control meansfurther including manually operable means for displacing at least one ofsaid spring means in such a direction as to change the force acting onthe pawl from said last-named spring means so that one of the springmeans may predominate to urge the pawl toward a selected one or" saidends of the recess.

5. In a ratchet mechanism, the combination of a member having a head andanother member rotatably mounted in said head, one of said membershaving a circular toothed surface and the other of said members having arecess open to said circular toothed surface, a pawl carried in saidrecess, said pawl being of smaller size than the recess to permitcircumferential displacement of the pawl and withdrawal from thecircular toothed surface, said recess having two ends adapted to engagethe pawl for receiving the thrust of the pawl, the ends f said recessconverging toward each other in a direction away from the circulartoothed surface, one end of the recess receiving the thrust of the pawlfor one direction of driving and the other end of the recess receivingthe thrust of the pawl for the other direction of driving, said pawlhaving an arcuate side having teeth adapted to concurrent drivingengagement with said circular toothed surface, all of said pawl teethbeing used for driving in both directions, and control means forbringing the pawl into reversible engagement with the circular toothedsurface, said control means including adjustable means carried by one ofsaid members and arranged for movement to different elevations in adirection paralleling the axis of rotation of the member mounted in thehead, said control means including means for directing the pawl towardeither selected end of said recess, said adjustable means being arrangedto act on the last-named means so that the lastnamed means directs thepawl toward one end of the recess when the adjustable means is at oneelevation and directs the pawl toward the other end of the recess whenthe adjustable means is at another elevation.

6. In a ratchet mechanism, the combination of a driving member having ahead, a work-turning member mounted in said head for rotation therein,reversible pawl means carried by said work-turning member for drivingengagement with said head, and control means engaging the pawl means fordirecting the pawl means in reversible engagement with the head, saidcontrol means including an adjustable member carried by one of saidwork-turning and driving members and having two operable positions in adirection substantially paralleling the axis of rotation of saidwork-turning member, said control means including resiliently-actingmeans adapted to bias'the pawl means to drive in a selected directionand operatively connecting said adjustable member to said pawl means,said adjustable member being arranged to displace saidresiliently-acting means so that the resiliently-acting means biases thepawl means to drive in one direction when the adjustable member is inone operable position and biases the pawl means to drive in the otherdirection when the adjustable member is in the other of said operablepositions.

7. A ratchet mechanism according to claim 6, wherein the control meansfurther includes a manually shiftable member carried by said drivingmember and having two positions relative to said driving member wherebythe direction of ratchet motion may be indexed, said manually shiftablemember being arranged to act on said adjustable member so that saidadjustable member is directed to one of its operable positions when themanually shit'table member is in one of its positions and directed tothe other of its operable positions when the manually shiftable memberis in the other of its positions.

8. In a ratchet mechanism, the combination of a member having a headwith inwardly extending teeth, a work-turning member rotatably mountedin said head, a reversible pawl carried by said work-turning member inposition to engage the teeth in said head, said pawl having a pluralityof teeth for engagement with the teeth in said head, said pawl beingadapted to transmit thrust in two directions through the pawl to theworkturning member, and control means for bringing the pawl intoreversible engagement with the teeth in said head, said control meansincluding an adjustable member mounted for movement to either of twooperable positions with respect to said work-turning member in thedirection of the axis of rotation of the work-turning member, saidcontrol means including means resiliently engaging the pawl for urgingthe pawl to drive in a selected direction, the last-named meansoperatively con necting the adjustable member and the pawl, saidadjustable member being arranged to move the last-named means accordingto the operable position of the adjustable member so that the last-namedmeans has a reversible action on the pawl.

9. In a ratchet mechanism, the combination of a memher having a headwith inwardly extending teeth, a workturning member rotatably mounted insaid head, a pawl carried by said work-turning member in position toengage the teeth of said head, said pawl having teeth for engaging theteeth of said head, the pawl being adapted for driving in bothdirections, and control means engaging the pawl for directing theratcheting action of the pawl, said control means including tworesiliently-acting members acting between the pawl and said workturningmember, one of said resiliently-acting members urging the pawl to drivein one direction and the other resiliently-acting member urging the pawlto drive in the other direction, the forces exerted on the pawl from theresiliently-acting members being of difi'erent magnitude, theresiliently-acting member of greater magnitude predominating to controlthe direction of driving, said control means including means forselectively displacing the resiliently-acting member of greatermagnitude to reduce its force on the pawl, whereby the resilientlyactingmember of lesser magnitude may control the direction of driving.

10. In a ratchet mechanism, the combination of a driving member having ahead with inwardly extending 7' teeth, a work-turning member rotatablymounted in sm'd head, a reversible one-piece pawl carried by saidworkturning member in position to engage the teeth in said head, saidpawl having a plurality of teeth for engaging the teeth in the head,said pawl being adapted to transmit thrust in two directions, relativeto the pawl, to the work-turning member, and control means for bringingthe pawl into reversible engagement with the teeth in said head, saidcontrol means including an adjustable member carried by one of saiddriving and work-turning members and arranged to have two operablepositions at difierent elevations in a direction paraileling the axis ofrotation of said work-turning memher, said control means including meansresponsive to the operable position of said adjustable member forselec-tively biasing the pawl to drive in either direction.

11. A ratchet mechanism according to claim 10, wherein the last-namedmeans comprises two spring 5 members acting on the pawl, one springmember urging the pawl to drive in one direction and the other springmember urging the pawl to drive in the other direction.

References Cited in the tile of this patent

1. IN A RATCHET MECHANISM, THE COMBINATION OF A DRIVING MEMBER HAVING AHEAD, A WORK-TURNING MEMBER MOUNTED FOR ROTATION IN SAID HEAD,REVERSIBLE PAWL MEANS CARRIED BY SAID WORK-TURNING MEMBER FOR DRIVINGENGAGEMENT WITH THE HEAD, AND CONTROL MEANS FOR DIRECTING THE PAWL MEANSIN REVERSIBLE ENGAGEMENT WITH THE HEAD, SAID CONTROL MEANS INCLUDING TWOYIELDABLE MEMBERS MOUNTED ON SAID WORK-TURNING MEMBER AND ACTING ON THEPAWL MEANS WITH UNEQUAL FORCE, ONE OF SAID YIELDABLE MEMBERS URGING THEPAWL MEANS IN A DIRECTION TO DRIVE ONE